On Sunday, a state trooper said blowing dust led to a "dirt blizzard" in eastern Wyoming that resulted in zero visibility for drivers on U.S. 85 south of Torrington. The gusts prompted state transportation officials to close the highway south of Torrington for about six hours Sunday until winds died down. Troopers said they responded to several crashes and found about 20 stranded drivers who had stopped because they couldn't see or who got stuck because they couldn't see they were veering off the road. No serious injuries were reported.